There are plenty of things that separate an elite cyclist from your average weekend warrior—a carbon fiber frame, a semi-permanent grimace, horse-sized lungs and a featherlight brain bucket. Until fairly recently, that is. The Specialized S3, with its low price-to-weight ratio, has totally changed the game, allowing Average Joes with shallower pockets the chance to wear a helmet that's lightweight, aerodynamic and well-ventilated for less than $200. But the S3 ($160) owes much to its top-of-the-line older brother, the elite-level Specialized S-Works Prevail ($250). Together, they represent two of the lightest lids on the market at their respective price points. That got us wondering, what exactly does the extra $90 get you? We put in some serious miles wearing both to find out.

Specialized S-Works Prevail ($250)
The new-for-2012 Prevail represented a huge leap forward in Specialized's helmet line. Designed by former Giro employees, the Prevail was meant to compete directly with—and on some level, to surpass—Giro's premium helmet, the 222-gram, 24-vent Aeon. According to Specialized, the Prevail weighs in at a scant 215 grams, which it achieves with 30 vents, dual-density EPS foam (lighter weight, lower density EPS liner on the top of the helmet where more surface area absorbs more impact, and higher density foam on the sides to strengthen against whacks) and a gorgeous-in-its-simplicity fitting system. The ventilation system lends the Prevail much of its distinctive look, with the "Mega Mouth" forehead grille front and center and huge, aligned vertical exhaust ports across the back. This keeps the whole shebang super lightweight and cool enough that it feels almost like wearing no helmet. The fitting system allows for three separate settings, which, combined, seem to fit almost any noggin. An easy-to-use micro-dial adjusts circumference with reassuring clicks in both directions, height is set by simply pulling out or pushing in two thin plastic pieces that hook the rear retention system into the body of the helmet, and a minimalist strap tightens and loosens with a single setting (and it's made with lightweight 4X DryLite webbing that won’t stretch out with sweat or water). The genius of the whole system is that it strips weight AND is no-nonsense. Fitting the Prevail is easier than any other high-performance helmet.

Specialized S3 ($160)
The S3 was the unlikely benefactor of many of the technological innovations that no doubt came via R&D for the Prevail. It has the same forehead grille, huge front vents and aligned vertical exhaust ports that give the Prevail its signature look and boasts the same exact retention system. It's slightly bulkier, though (Specialized claims 249 grams), with heavier, uniform density EPS foam throughout the top and sides, two fewer side vents and a slightly less tapered, aerodynamic rear.

OverallWeight: Something that was perhaps definitive in our two-month-long testing period was that the measured weights of the S-Works Prevail and S3 were so similar. On a super accurate baking scale, the S3 read out 239 grams (10 grams lighter than manufacturer specs) and the Prevail said 229 grams (15 grams heavier than manufacturer specs). A 10-gram weight difference is so negligible as to not be a factor at all.Fit: Since they use the same retention system, both helmets were super easy to dial in, though the Prevail felt ever-so-slightly snugger. Getting each one set correctly took a minute or less, and adjustments were never necessary since the straps' 4x DryLite webbing didn't stretch, not even in the rain or on humid, sweaty rides.Ventilation: There was no clear difference between the two helmets. As expected, the Prevail had excellent airflow. The S3, with a nearly identical system, performed just as admirably, allowing plenty of air to whoosh through for cooling purposes.Aerodynamics: There's no doubt in my mind that the Prevail is more aerodynamic than the S3. You can see it's somewhat less bulky, it tapers more in the rear, and there's a tiny extra vent scooped from either side that's surely the result of extensive wind tunnel testing. In fact, when the Prevail was first released, Specialized claimed that a Prevail-wearing rider with a consistent 250W output would be 250 meters ahead of an equivalent rider wearing a Giro Ionos after an hour, based on helmet aerodynamics alone. At my riding level, though (that is, with my races consisting of flying past fellow commuters), these minute aerodynamic differences matter very little.

Conclusion
In the end, $90 doesn't buy you a whole lot more—10 grams, a little less bulk and slightly better aerodynamics. This isn't a knock against the Prevail, which is most certainly one of the best bike helmets available anywhere right now. It's simply to say that, at $160, the S3 is a much better value. It destroys its competition weight-wise (Catlike Whisper, Giro Ionos and Uvex FP 3.0 all weigh around 300 grams), has the Prevail's same fuss-free retention system, and retains much of the ventilation design that sucks wind through the more expensive lid. My advice is to leave the S-Works Prevail to the pro peloton. The S3 is a more-than-adequate, do-it-all helmet at an amazing price point. Plus, it even comes with a visor for taking on singletrack.